Reposition terminals for circuit breaker base extension



Aug. 16, 1960 REPOS Filed NOV. 23, 1956 W. H. EDMUNDS ITION TERMINALSFOR CIRCUIT BREAKER BASE EXTENSION 4 Sheets-Sheet l Arman 6% Aug. 16,1960 w. H. EDMUNDS REPOSITION TERMINALS FOR CIRCUIT BREAKER BASEEXTENSION 4 Sheets-Sheet 2 Filed Nov. 23, 1956 Aug. 16, 1960 Filed NOV.23, 1956 W H. EDMUNDS REIPOSI'I'ION TERMINALS FOR CIRCUIT BREAKER BASEEXTENSION 4 Sheets-Sheet 3 I DJ gamma vs A frat V 76 1 1960 w H. EDMUNDS2,949,516

REPOSITION TERMINALS FOR CIRCUIT BREAKER BASE EXTENSION Filed Nov. 23,1956 4 Sheets-Sheet 4 ll 36 ll 33 w 70 76 W WM ,zwza Mm W W BY M I WUnited States Patent REPOSITION TERMINALS FOR CIRCUIT BREAKER BASEEXTENSION William Harold Edmunds, Havertown, 'Pa., assignor to I-T-ECircuit Breaker Company, Philadelphia, Pa., a corporation ofPennsylvania Filed Nov. 23, 1956, Ser. No. 623,833

Claims. (Cl. 200-114) My invention relates to a circuit interrupter ofthe type shown in my copending applications Serial No. 461,378, filedOctober 11, 1954, and Serial No. 622,042, filed November 16, 1956,wherein a current limiting device and series connected circuit breakerare electrically and mechanically coordinated and is more specificallyrelated to a terminal construction for the above noted type of devicewherein its terminals have the same positioning as the terminals of thestandard circuit breaker.

The combination of a series connected circuit breaker and currentlimiting device has been set forth in my copending application SerialNo. 461,378, above noted, and a construction wherein the currentlimiters and circuit breaker are placed inindividual housings which areremovably connected to one another is set forth in copendingapplications Serial No. 472,969, filed December -3, 1954, now Patent No.2,888,535, and Serial No. 622,042, above noted.

In essence, this combination allows the use of a circuit breaker havinga lower interrupting rating than the short circuit capacity of thecircuit breaker wherein the circuit breaker is provided with thermaltrip units for opening a circuit after prolon ed overloads and aninstantaneous trip unit for opening the circuit under relatively lowfault values. When a strong fault appears or a fault which exceeds apredetermined cross-over point, the series connected current limitingfuse operates to interrupt the circuit rather than the circuit breakerwhich may not be large enough to interrupt this fault value. v

As well as being electrically coordinated as seen above, the two devicesare also mechanically coordinated in that operation of the currentlimiting fuse of any phase (when operating in a multiphase system) willautomatically trip the circuit breaker contacts of each phase.

As set forth in the above noted application Serial No. 622,042, the baseof a standard circuit breaker may be extended and provided withdisconnect contacts so that current limiting devices may be mounted inseries with the circuit breaker by disconnect contact engagement betweena circuit breaker trip unit disconnect contact and the additionalcontact attached to the base. Hence, the terminals of the combinedinterrupter will be the original circuit breaker terminal on the circuitbreaker side away from the base while the second terminal will bealigned with the disconnect contact added to the base extension of thecircuit breaker. Thus the distance between the first and second currentinterrupter terminals is now greater than the distance between theoriginal terminals of the circuit breaker and it will be impossible tomount this adapted current interrupter in a switchboard having terminaldistances which are given'by the terminal spacing of the standardcircuit breaker device.

That is to say, the switchboard terminals which could be of the plug-intype having protruding studs extending from their mounting blocks arespaced from one another so that the spacing distance exactly correspondsto the terminal spacing of the standard type circuit breaker. When,however, a base extension is utilized for mounting the current limitingdevices at the end of the circuit breaker as set forth in applicationSerial No. 622,042 the terminal spacing of the current interrupter isincreased and it would therefore require a new panel board constructionwherein the terminal spacing is increased accordingly.

The principle of my invention is to construct a base extension whichcould be an added member or could be an integral part of the circuitbreaker base for a circuit breaker wherein the disconnect contact of theextension is electrically connected to a second disconnect contact onthe bottom of the circuit breaker base which is in registering alignmentwith the original circuit breaker trip unit terminal. Thus in my novelconstruction, the terminal spacing of a circuit breaker which iselectrically and mechanically coordinated with a current limiting devicewill be exactly the same as that of the circuit breaker itself. Hence inan existing installation, it is now only necessary to remove thestandard type of circuit breaker and replace it with the currentinterrupting device set forth in application Serial No. 622,042 withoutdisturbing the bus or cable connections in the back of the switchboard.

Accordingly, a primary object of my invention is to construct the baseextension of a combined circuit breaker and current limiting device sothat the terminal spacing will be the same as the terminal spacing ofthe circuit breaker itself.

Another object of my invention is to provide a novel constructionwherein standard types of circuit breakers and circuit breakers adaptedto be coordinated with current limiting fuses are interchangeablyconnected to a given panel board.

These and other objects of my invention will become apparent from thefollowing description taken in connection with the drawings in whichFigures 1 and 1A are perspective views showing a circuit interruptingdevice comprising a circuit breaker contained within a first housing anda current limiting device contained within a second and removablehousing.

Figure 2 is an exploded perspective view of the current limiting deviceand housing of Figure 1.

Figure 3 shows a cross-sectional view through one phase of Figure 1.

Figure 4 shows a fragmentary top view of Figure 3 where a pin isinserted in the interlock rod to defeat the interlock.

Figure 5 is a second embodiment of my novel invention.

Figure 6 is an enlarged view in cross-section of the base constructionof Figure 4-.

Referring first to Figure 1, a circuit breaker housing 20 has anextension 21 connectible to one end thereof by means of screws such asscrews 24 and 25 which pass through openings 28 and 29 respectively,which fasten into cooperating openings in circuit breaker housing 20.

if desired, extension 21 could be an integral part of the circuitbreaker base as is shown in Figure 1A.

In this application, therefore, the extended base is intended to meaneither an extra component added to a base or an extension which is anintegral partof the base.

Contained with circuitv breaker housing 20 is an 'operating mechanism ofany desired type such as that shown in my U.S. Patent No. "2,574,093which is operable by operating handle 30 for operating a pair ofcontacts for each phase of the circuit breaker. Each of the pairs ofcontacts of each phase is then terminated on one side by disconnectcontacts 31, 32 and a contact 33, which cannot be seen in Figureljrespectively.

The extension -21 provides additional disconnect contacts 34, 35 and 36which cooperate with contacts 31, 32 and 33 respectively for connectinga current limiting device in series with each of the circuit breakerphases.

Each of disconnect contacts 31 and 36 are of the tulip clip type such asthat described in copending application Serial No. 536,586, filedSeptember 26, 1955, and assigned to the assignee of the instantinvention, which are constructed to receive a stud in electrical andmechanical engagement.

However, disconnect contacts 31 through 36 could be of any desired type.

Current limiting devices for cooperating with each of the circuitbreaker phases are housed within housing 37. Figure 2 more specificallyshows these current limiting devices as fuses 38, 39 and 40 which areprovided with disconnect studs 41-42, 4344, 45-46 respectively. As seenin Figure 1, fuse 40 is connected to its corresponding phase byconnection of disconnects 41 and 42, and disconnects 36 and 33respectively. In a similar manner, disconnects 43, 44 and 45, 46 ofFigure 2 will,

cooperate with disconnects 35, 32 and 34, 31 respectively of Figure 1.

Fuses 38, 39 and 40 are maintained in housing 37 by retaining plate 47which is fastened to housing 37 by screws 48 and 49 as seen in Figure 2and described in copending application Serial No. 582,552, filed May 3,1956, now Patent No. 2,905,791 and the assembled housing is connected tothe circuit breaker housing by screws 50 and 51 which pass throughapertures 52 and 53 respectively and into tapped openings 54 and 55 ofextension 21 as seen in Figure 1.

As may be seen in the above noted copending application Serial No.472,969 each ot fuses 38, 39 and 40 are provided with a striker pin suchas striker pin 85 of fuse 40 which is ejected from the fuse uponoperation thereof. The striker pins are positioned to pass through acooperating aperture in its respective disconnect, such as aperture 56of disconnect 42 which cooperates with striker pin 85.

An auxiliary tripper bar 57 is pivotally mounted within housing 37 asseen in Figures 1 and 2 and as best seen in Figure 2, tripper bar 57 asextensions 58, 59 and 60 thereon which are positioned to be engaged bythe striker pins of fuses 38, 39 and 40 respectively upon operationthereof.

A further extension 61 is fastened to auxiliary tripper bar 57 which, aswill be seen hereinafter, is biased into operative engagement with thetripper bar of the circuit breaker by biasing spring 61a.

Figure 3 shows a cross sectional view of the assembled components ofFigure 1 when taken through the phase including fuse 40.

As seen in Figure 3 which shows screw 24 fastened to circuit breakerhousing 20, a tulip clip type contact 62 is electrically connected tocontact 36 and is fastened within housing 21 in any desired manner.Clearly, a set of disconnects similar to disconnect 62 will be providedfor each of disconnects 34 and 35.

The circuit breaker is provided with a similar set of disconnects suchas disconnect contact 63 wherein disconnects 62 and 63 cooperate forplug in engagement with studs 64 and 65 respectively of mounting blocks66 and 67 which may be fastened within a switch board. Clearly, each ofthe other phases will be provided with similar sets of disconnects forcooperating with corresponding mounting blocks.

As an alternative, Figure 3 shows that a straight terminal 68 could bebrought out as seen in dotted lines where connection to the currentinterrupting device is made at lead connecting means 69.

The current path of the phase shown in Figure 3 ineludes stud 65,circuit breaker tulip clip 63, stationary contact 70, movable contact ofcontact arm 71, a pigtail (not shown) which connects contact arm 71 toconductor 72, heater 73, coil 74, conductor 75, tulip clip 33, stud 42,fuse 40, stud 41, tulip clip 36, tulip clip 62, and stud 64.

Coil 74 has a pivotally mounted armature 76 and a plunger 77 associatedtherewith, these components comprising the magnetic trip unit. Heater 73has bimetal 78 and adjusting screw 79 associated therewith, thesecomponents comprising the thermal-trip unit.

A tripper bar 80 is then seen in Figure 3 as having member 81 fastenedthereto which carries adjusting screw 79 in cooperating alignment withbimetal 78 and is itself aligned with plunger 77.

Member 81 has one end thereof protruding into slot 82 of trip rod 83 andis rotatable in a counterclockwise direction within slot 82.

The operating mechanism 84 has a latch member 85 connected thereto andconstructed to be latched by tripper bar 80. When tripper bar 80 isrotated in a counterclockwise direction, however, latch member 85 willbe unlatched to allow mechanism 84 to disengage the circuit breakercooperating contacts of each phase since mechanism 84 is constructed tobe common to each phase.

In the event of a prolonged overload, heater 73 will cause bimetal 78 todeflect into engagement with screw 79 to cause counterclockwise rotationof tripper bar 80 and tripping of the circuit breaker contacts.

Under fault conditions, coil 74 will create a strong magnetic field tocause armature 76 to drive plunger 77 into engagement with member 81,thus rotating bar 80 counterclockwise to effect instantaneous trippingof the circuit breaker contacts.

Figure 3 further shows the striker pin 85' of fuse 40 as beingpositioned in registry with aperture 56in disconnect 42 and extension 60of auxiliary tripper bar 57 (see Figure 2).

When fuse 40 is operated (on faults above a predetermined value),striker pin 85' is ejected into engagement with extension 60 to rotateauxiliary tripper bar 57 (Figure 2) clockwise against the biasing forceof spring 61a. This rotation will then remove extension 61 from trip 85aof trip rod 83 and allow biasing spring 86 to drive trip rod 83 to theleft and rotate tripper bar 80 counterclockwise for tripping the circuitbreaker contacts.

Thus, upon operation of one of the current limiting fuses such as fuse40, the circuit breaker contacts will be disengaged to prevent singlephasing and to disconnect the circuit.

It is important to note that the same action would be obtained if thefuse housing 37 were disconnected from the circuit breaker housing 20.That is, extension 61 of tripper 'bar 57 would be removed from tip 85aof link 83 to allow subsequent rotation of tripper bar 80.

Hence, in this construction wherein the fuse housing 37 is connected atthe end of circuit breaker housing 20, the circuit breaker cooperatingcontacts will be disengaged responsive either to operation of any of thefuses or to removal of the fuse housing.

In the case of Figure 3, it is seen that the spacing between switchboardmounting blocks 66 and 67 and their studs 64 and 65 respectively isdetermined by the relative spacing between terminals 62 and 63. If thecircuit breaker 20 were a standard circuit breaker and did not includethe extended base 21, however, the terminal spacing would be given byterminals 63 and a terminal which would be in registry with circuitbreaker disconnect contact 33. Thus, in adding the base extension 21 andits disconnect contact 36 to circuit breaker 20, the terminal spacing ofthe device is increased over that of the circuit breaker itself. Hence,if the circuit breaker 20 of Figure 3 had been previously mounted in aswitchboard by disconnects such as 63 and a disconnect in registry withdisconmeet 33, the panel board would have (to be considerably altered inorder to accommodate the increased terminal spacing.

Figure 4 specifically illustrates my novel invention and the manner inwhich my novel invention allowsthe connecting blocks 66 and 67 and theircorresponding studs 64 and 65 respectively to be connectible to either astandard circuit breaker or to a circuit breaker having a base extensionfor mounting fuse devices as shown in Figure3.

It is to be noted that in the following description; the use of tuliptype disconnects is set forth for illustrative purposes. However, mynovel invention would be applicable with the use of any type of terminalconstruction.

In the case of Figure 4, it is seen that disconnect 36 which is fastenedto the extended base 21 has a current conducting member 90 connected totulip clip 62 which is now offset to be in registry with terminal 33.

Figure 5 which is a bottom view of Figure 4 shows that the tulip cliptype disconnects 91 and 92 for the other two phases of the three phasedevice of Figure 4 are offset in a manner similar to that shown forterminal 62 and are connected to their corresponding disconnects 35 and34 re-' speetively by connecting members 93 and 94 respectively.Clearly, terminals 91 and 92 will be in registering relationship orcoaxial relationship with respect to the circuit breaker trip unitdisconnects which may be seen as disconnects 32 and 31 respectively inFigure l.

The manner in which connecting member 90 is supported within the baseextension 21 may be best seen in Figure 6 which shows a fragmentarycross-sectional view along the lines 66 of Figure 5.

Thus, Figure 6 shows the jumper 90 as being maintained against thecurrent carrying bushing 95 by means of bolt 96 which is in threadedengagement with stud 97. Stud 97 as shown in Figure 6 is engageable withtulip clip 36. Hence, the threaded engagement between bolt 96 and stud97 maintains a portion of jumper 90 in both electrical engagement withstud 97 and mechanical engagement with housing 21. Further mechanicalsupport for jumper 90 may be obtained by screw means 98 which isthreaded into housing 21.

Jumper 90 is terminated by a stud 99 which is in registry with stud 100which has circuit breaker trip unit disconnect 33 attached thereto, stud100 being connected to conductor 75 which, as seen in Figure 3, isconnected to the trip mechanism of the circuit breaker.

Stud 99 then has the tulip clip type disconnect 62 secured thereto bythe garter spring 101 in the manner set I forth in the Us. Patent2,805,294 issued to W. H. Ed-

munds entitled Mounting Block for Circuit Breaker and the other end ofdisconnect 62 is adapted to receive a stud connecting means such as stud64 of Figure 4 of the mounting block 66.

It is now clear with reference to Figures 4, 5 and 6 that the combinedcircuit breaker and current limiter will have the same terminal spacingas does a standard circuit breaker since these terminals are in registrywith the standard circuit breaker terminal positions. Thus, as seen inFigure 4, the same switchboard construction which includes mountingblocks 66 and 67 may be used to mount either standard circuit breakersor circuit breakers co ordinated with current limiting devices mountedon an extended base of the circuit breaker.

Although I have here described preferred embodiments of my novelinvention, many modifications and variations will now be apparent tothose skilled in the art. I prefer therefore to be limited not by thespecific disclosure herein, but only by the appended claims.

I claim:

1. In combination; a circuit breaker having an extended base and aterminal; said circuit breaker having a pair of cooperable contactsmovable between an engaged and a disengaged position, and a disconnectcontact; said disconnect contact being in registry with a circuitbreaker terminal position; said extended base carrying a disconnectcontact; said circuit breaker disconnect contact and said extended basedisconnect contact being constructed to electrically connect a currentlimiting device in series with said pair of cooperating contacts whencorresponding disconnect contacts of said current limiting device engagesaid circuit breaker and base disconnect contacts; said terminal beingelectrically connected to said extended base disconnect contact andpositioned in registry with said circuit breaker disconnect contact.

-' 2. In combination; a circuit breaker having an extended base andaterminal; said circuit breaker having a pair of cooperable contactsmovable between an engaged and a disengaged position, trip mechanism formechanically coordinating said circuit breaker with a current limitingdevice, and a disconnect contact; said disconnect contact being inregistry with a circuit breaker terminal position; said extended basecarrying a disconnect contact; said circuit breaker disconnect contactand said extended base disconnect contact being constructed toelectrically connect a current limiting device in series with said pairof cooperating contacts when corresponding disconnect contacts of saidcurrent limiting device engage said circuit breaker and extended basedisconnect contacts; said termi nal being electrically connected to saidbase disconnect contact and positioned in registry with said circuitbreaker disconnect contact; panel boards being adapted for pluginarrangement with said circuit breaker alone being cooperable with saidcurrent interrupter having the same terminal position.

3. In combination; a circuit breaker having an extended base and aterminal; said circuit breaker having a pair of cooperable contactsmovable between an engaged and a disengaged position and a disconnectcontact; said circuit breaker having a first and second terminalposition at either end thereof; said first terminal position being atthe end of said circuit breaker opposite said extended base end; saidextended base carrying a disconnect contact; said circuit breakerdisconnect contact and said extended base disconnect contact beingconstructed to electrically connect a current limiting device in serieswith said pair of cooperating contacts when corresponding disconnectcontacts of said current limiting device engage said circuit breaker andextended base disconnect contacts; said terminal being electricallyconnected to said base disconnect contact and positioned in registrywith said circuit breaker second terminal position.

4. In combination; a multiphase circuit breaker having an extended baseand a terminal for each phase; each phase of said circuit breaker havinga pair of cooperable contacts movable between an engaged and adisengaged position, and a disconnect contact; each of said disconnectcontacts being in registry with corresponding circuit breaker terminalpositions; said extended base carrying a disconnect contact for eachphase of said multiphase circuit breaker; each of said circuit breakerdisconnect contacts and said extended base disconnect contacts beingconstructed to electrically connect a current limiting device in serieswith corresponding pairs of cooperating contacts when correspondingdisconnect contacts of said current limiting device engage said circuitbreaker and extended base disconnect contacts; each of said terminalsfor each phase being electrically connected to a corresponding basedisconnect contact and positioned in registry with a correspondingcircuit breaker disconnect contact.

5. In combination; a circuit breaker having an extended base and aterminal; said circuit breaker having a pair of cooperable contactsmovable between an engaged and a disengaged position, and a disconnectcontact; said disconnect contact being in registry with a circuitbreaker terminal position; said extended base carrying a disconnectcontact; said circuit breaker disconnect contact and said extended basedisconnect contact being constructed to electrically connect a fusibledevice in series with said pair of cooperating contacts whencorresponding disconnect contacts of said fusible device engage saidcircuit breaker and extended base disconnect contacts; said termi-References Cited in the file of this patent UNITED STATES PATENTS Auelet al Nov. 1, 1910 Van Valkenburg July 3, 1917 Wyrnan Oct. 13, 1925 10Milano Oct. 2, 1928 Benjamin Feb. 5, 1929 8 Corbett Mar. 2, 1937 SchmidtFeb. 27, 1940 Linde May 27, 1941 Dannenberg Sept. 28, 1943 Cataldo eta1. May 13, 1947 Dannenberg June 14, 1949 Spiro July 12, 1949 KozackaMay 28, 1957 Swain et a1. July 23, 1957 FOREIGN PATENTS Great BritainApr. 25, 1935

